Re: [PATCH 21/21] xfsprogs: implement the upper half of parent pointers

[Allison Henderson <allison.henderson@oracle.com>]

On 05/08/2018 10:45 AM, Darrick J. Wong wrote:
> On Mon, May 07, 2018 at 09:41:19PM -0700, Allison Henderson wrote:
>> From: "Darrick J. Wong" <darrick.wong@oracle.com>
>>
>> Add ioctl definitions to libxfs, build the necessary helpers into
>> libfrog and libhandle to iterate parents (and parent paths), then wire
>> up xfs_scrub to be able to query parent pointers from userspace.  The
>> goal of this patch is to exercise userspace, and is nowhere near a
>> complete solution.  A basic xfs_io parent command implementation
>> replaces ... whatever that is that's there now.
>>
>> Totally missing: actual support in libxfs for working with parent ptrs
>> straight off the disk (mkfs, xfs_db, xfs_repair).
>>
>> [achender: Minor syntax adjustments to sew solution in actual support
>> 	   in libxfs for working with parent ptrs]
>>
>> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
>> Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
>> ---
>>   include/handle.h   |   2 +
>>   include/parent.h   |  18 ++
>>   include/path.h     |  19 +++
>>   io/parent.c        | 471 ++++++++++++++---------------------------------------
>>   libfrog/paths.c    | 136 ++++++++++++++++
>>   libhandle/Makefile |   2 +-
>>   libhandle/handle.c |   7 +-
>>   libhandle/parent.c | 325 ++++++++++++++++++++++++++++++++++++
>>   libxfs/xfs_fs.h    |   8 +
>>   scrub/inodes.c     |  26 +++
>>   scrub/inodes.h     |   2 +
>>   scrub/phase5.c     |   9 +-
>>   12 files changed, 661 insertions(+), 364 deletions(-)
>>
>> diff --git a/include/handle.h b/include/handle.h
>> index 49f1441..00aa43d 100644
>> --- a/include/handle.h
>> +++ b/include/handle.h
>> @@ -52,6 +52,8 @@ extern int  fssetdm_by_handle (void *__hanp, size_t __hlen,
>>   
>>   void fshandle_destroy(void);
>>   
>> +int handle_to_fsfd(void *hanp, char **path);
>> +
>>   #ifdef __cplusplus
>>   }
>>   #endif
>> diff --git a/include/parent.h b/include/parent.h
>> index 85cef85..33f8d85 100644
>> --- a/include/parent.h
>> +++ b/include/parent.h
>> @@ -28,4 +28,22 @@ typedef struct parent_cursor {
>>   	__u32	opaque[4];      /* an opaque cookie */
>>   } parent_cursor_t;
>>   
>> +struct path_list;
>> +
>> +typedef int (*walk_pptr_fn)(struct xfs_pptr_info *pi, struct xfs_parent_ptr *pptr,
>> +		void *arg);
>> +typedef int (*walk_ppath_fn)(const char *mntpt, struct path_list *path,
>> +		void *arg);
>> +
>> +#define WALK_PPTRS_ABORT	1
>> +int fd_walk_pptrs(int fd, walk_pptr_fn fn, void *arg);
>> +int handle_walk_pptrs(void *hanp, size_t hanlen, walk_pptr_fn fn, void *arg);
>> +
>> +#define WALK_PPATHS_ABORT	1
>> +int fd_walk_ppaths(int fd, walk_ppath_fn fn, void *arg);
>> +int handle_walk_ppaths(void *hanp, size_t hanlen, walk_ppath_fn fn, void *arg);
>> +
>> +int fd_to_path(int fd, char *path, size_t pathlen);
>> +int handle_to_path(void *hanp, size_t hlen, char *path, size_t pathlen);
>> +
>>   #endif
>> diff --git a/include/path.h b/include/path.h
>> index 88dc44b..cbe4e19 100644
>> --- a/include/path.h
>> +++ b/include/path.h
>> @@ -70,4 +70,23 @@ typedef struct fs_cursor {
>>   extern void fs_cursor_initialise(char *__dir, uint __flags, fs_cursor_t *__cp);
>>   extern fs_path_t *fs_cursor_next_entry(fs_cursor_t *__cp);
>>   
>> +/* Path information. */
>> +
>> +struct path_list;
>> +struct path_component;
>> +
>> +struct path_component *path_component_init(const char *name);
>> +void path_component_free(struct path_component *pc);
>> +int path_component_change(struct path_component *pc, void *name,
>> +		size_t namelen);
>> +
>> +struct path_list *path_list_init(void);
>> +void path_list_free(struct path_list *path);
>> +void path_list_add_parent_component(struct path_list *path,
>> +		struct path_component *pc);
>> +void path_list_add_component(struct path_list *path, struct path_component *pc);
>> +void path_list_del_component(struct path_list *path, struct path_component *pc);
>> +
>> +ssize_t path_list_to_string(struct path_list *path, char *buf, size_t buflen);
>> +
>>   #endif	/* __PATH_H__ */
>> diff --git a/io/parent.c b/io/parent.c
>> index 55b8b49..ad51fe6 100644
>> --- a/io/parent.c
>> +++ b/io/parent.c
>> @@ -21,366 +21,105 @@
>>   #include "path.h"
>>   #include "parent.h"
>>   #include "handle.h"
>> -#include "jdm.h"
>>   #include "init.h"
>>   #include "io.h"
>>   
>> -#define PARENTBUF_SZ		16384
>> -#define BSTATBUF_SZ		16384
>> -
>>   static cmdinfo_t parent_cmd;
>> -static int verbose_flag;
>> -static int err_status;
>> -static __u64 inodes_checked;
>>   static char *mntpt;
>>   
>> -/*
>> - * check out a parent entry to see if the values seem valid
>> - */
>> -static void
>> -check_parent_entry(xfs_bstat_t *bstatp, parent_t *parent)
>> -{
>> -	int sts;
>> -	char fullpath[PATH_MAX];
>> -	struct stat statbuf;
>> -	char *str;
>> -
>> -	snprintf(fullpath, parent->p_reclen, _("%s%s"), mntpt,
>> -				((char*)parent)+sizeof(struct parent));
>> -
>> -	sts = lstat(fullpath, &statbuf);
>> -	if (sts != 0) {
>> -		fprintf(stderr,
>> -			_("inode-path for inode: %llu is incorrect - path \"%s\" non-existent\n"),
>> -			(unsigned long long) bstatp->bs_ino, fullpath);
>> -		if (verbose_flag) {
>> -			fprintf(stderr,
>> -				_("path \"%s\" does not stat for inode: %llu; err = %s\n"),
>> -				fullpath,
>> -			       (unsigned long long) bstatp->bs_ino,
>> -				strerror(errno));
>> -		}
>> -		err_status++;
>> -		return;
>> -	} else {
>> -		if (verbose_flag > 1) {
>> -			printf(_("path \"%s\" found\n"), fullpath);
>> -		}
>> -	}
>> -
>> -	if (statbuf.st_ino != bstatp->bs_ino) {
>> -		fprintf(stderr,
>> -			_("inode-path for inode: %llu is incorrect - wrong inode#\n"),
>> -		       (unsigned long long) bstatp->bs_ino);
>> -		if (verbose_flag) {
>> -			fprintf(stderr,
>> -				_("ino mismatch for path \"%s\" %llu vs %llu\n"),
>> -				fullpath,
>> -				(unsigned long long)statbuf.st_ino,
>> -				(unsigned long long)bstatp->bs_ino);
>> -		}
>> -		err_status++;
>> -		return;
>> -	} else if (verbose_flag > 1) {
>> -		printf(_("inode number match: %llu\n"),
>> -			(unsigned long long)statbuf.st_ino);
>> -	}
>> -
>> -	/* get parent path */
>> -	str = strrchr(fullpath, '/');
>> -	*str = '\0';
>> -	sts = stat(fullpath, &statbuf);
>> -	if (sts != 0) {
>> -		fprintf(stderr,
>> -			_("parent path \"%s\" does not stat: %s\n"),
>> -			fullpath,
>> -			strerror(errno));
>> -		err_status++;
>> -		return;
>> -	} else {
>> -		if (parent->p_ino != statbuf.st_ino) {
>> -			fprintf(stderr,
>> -				_("inode-path for inode: %llu is incorrect - wrong parent inode#\n"),
>> -			       (unsigned long long) bstatp->bs_ino);
>> -			if (verbose_flag) {
>> -				fprintf(stderr,
>> -					_("ino mismatch for path \"%s\" %llu vs %llu\n"),
>> -					fullpath,
>> -					(unsigned long long)parent->p_ino,
>> -					(unsigned long long)statbuf.st_ino);
>> -			}
>> -			err_status++;
>> -			return;
>> -		} else {
>> -			if (verbose_flag > 1) {
>> -			       printf(_("parent ino match for %llu\n"),
>> -				       (unsigned long long) parent->p_ino);
>> -			}
>> -		}
>> -	}
>> -}
>> -
>> -static void
>> -check_parents(parent_t *parentbuf, size_t *parentbuf_size,
>> -	     jdm_fshandle_t *fshandlep, xfs_bstat_t *statp)
>> -{
>> -	int error, i;
>> -	__u32 count;
>> -	parent_t *entryp;
>> -
>> -	do {
>> -		error = jdm_parentpaths(fshandlep, statp, parentbuf, *parentbuf_size, &count);
>> -
>> -		if (error == ERANGE) {
>> -			*parentbuf_size *= 2;
>> -			parentbuf = (parent_t *)realloc(parentbuf, *parentbuf_size);
>> -		} else if (error) {
>> -			fprintf(stderr, _("parentpaths failed for ino %llu: %s\n"),
>> -			       (unsigned long long) statp->bs_ino,
>> -				strerror(errno));
>> -			err_status++;
>> -			break;
>> -		}
>> -	} while (error == ERANGE);
>> -
>> -
>> -	if (count == 0) {
>> -		/* no links for inode - something wrong here */
>> -	       fprintf(stderr, _("inode-path for inode: %llu is missing\n"),
>> -			       (unsigned long long) statp->bs_ino);
>> -		err_status++;
>> -	}
>> -
>> -	entryp = parentbuf;
>> -	for (i = 0; i < count; i++) {
>> -		check_parent_entry(statp, entryp);
>> -		entryp = (parent_t*) (((char*)entryp) + entryp->p_reclen);
>> -	}
>> -}
>> -
>>   static int
>> -do_bulkstat(parent_t *parentbuf, size_t *parentbuf_size, xfs_bstat_t *bstatbuf,
>> -	    int fsfd, jdm_fshandle_t *fshandlep)
>> +pptr_print(
>> +	struct xfs_pptr_info	*pi,
>> +	struct xfs_parent_ptr	*pptr,
>> +	void			*arg)
>>   {
>> -	__s32 buflenout;
>> -	__u64 lastino = 0;
>> -	xfs_bstat_t *p;
>> -	xfs_bstat_t *endp;
>> -	xfs_fsop_bulkreq_t bulkreq;
>> -	struct stat mntstat;
>> +	char			buf[XFS_PPTR_MAXNAMELEN + 1];
>>   
>> -	if (stat(mntpt, &mntstat)) {
>> -		fprintf(stderr, _("can't stat mount point \"%s\": %s\n"),
>> -			mntpt, strerror(errno));
>> -		return 1;
>> +	if (pi->pi_flags & XFS_PPTR_OFLAG_ROOT) {
>> +		printf(_("Root directory.\n"));
>> +		return 0;
>>   	}
>>   
>> -	bulkreq.lastip  = &lastino;
>> -	bulkreq.icount  = BSTATBUF_SZ;
>> -	bulkreq.ubuffer = (void *)bstatbuf;
>> -	bulkreq.ocount  = &buflenout;
>> -
>> -	while (xfsctl(mntpt, fsfd, XFS_IOC_FSBULKSTAT, &bulkreq) == 0) {
>> -		if (*(bulkreq.ocount) == 0) {
>> -			return 0;
>> -		}
>> -		for (p = bstatbuf, endp = bstatbuf + *bulkreq.ocount; p < endp; p++) {
>> -
>> -			/* inode being modified, get synced data with iget */
>> -			if ( (!p->bs_nlink || !p->bs_mode) && p->bs_ino != 0 ) {
>> -
>> -				if (xfsctl(mntpt, fsfd, XFS_IOC_FSBULKSTAT_SINGLE, &bulkreq) < 0) {
>> -				    fprintf(stderr,
>> -					  _("failed to get bulkstat information for inode %llu\n"),
>> -					 (unsigned long long) p->bs_ino);
>> -				    continue;
>> -				}
>> -				if (!p->bs_nlink || !p->bs_mode || !p->bs_ino) {
>> -				    fprintf(stderr,
>> -					  _("failed to get valid bulkstat information for inode %llu\n"),
>> -					 (unsigned long long) p->bs_ino);
>> -				    continue;
>> -				}
>> -			}
>> -
>> -			/* skip root */
>> -			if (p->bs_ino == mntstat.st_ino) {
>> -				continue;
>> -			}
>> -
>> -			if (verbose_flag > 1) {
>> -			       printf(_("checking inode %llu\n"),
>> -				       (unsigned long long) p->bs_ino);
>> -			}
>> -
>> -			/* print dotted progress */
>> -			if ((inodes_checked % 100) == 0 && verbose_flag == 1) {
>> -				printf("."); fflush(stdout);
>> -			}
>> -			inodes_checked++;
>> -
>> -			check_parents(parentbuf, parentbuf_size, fshandlep, p);
>> -		}
>> -
>> -	}/*while*/
>> -
>> -	fprintf(stderr, _("syssgi bulkstat failed: %s\n"), strerror(errno));
>> -	return 1;
>> +	memcpy(buf, pptr->xpp_name, pptr->xpp_namelen);
>> +	buf[pptr->xpp_namelen] = 0;
>> +	printf(_("p_ino    = %llu\n"), (unsigned long long)pptr->xpp_ino);
>> +	printf(_("p_gen    = %u\n"), (unsigned int)pptr->xpp_gen);
>> +	printf(_("p_reclen = %u\n"), (unsigned int)pptr->xpp_namelen);
>> +	printf(_("p_name   = \"%s\"\n\n"), buf);
>> +	return 0;
>>   }
>>   
>> -static int
>> -parent_check(void)
>> +int
>> +print_parents(
>> +	struct xfs_handle	*handle)
>>   {
>> -	int fsfd;
>> -	jdm_fshandle_t *fshandlep;
>> -	parent_t *parentbuf;
>> -	size_t parentbuf_size = PARENTBUF_SZ;
>> -	xfs_bstat_t *bstatbuf;
>> -
>> -	err_status = 0;
>> -	inodes_checked = 0;
>> -
>> -	sync();
>> -
>> -        fsfd = file->fd;
>> -
>> -	fshandlep = jdm_getfshandle(mntpt);
>> -	if (fshandlep == NULL) {
>> -		fprintf(stderr, _("unable to open \"%s\" for jdm: %s\n"),
>> -		      mntpt,
>> -		      strerror(errno));
>> -		return 1;
>> -	}
>> -
>> -	/* allocate buffers */
>> -        bstatbuf = (xfs_bstat_t *)calloc(BSTATBUF_SZ, sizeof(xfs_bstat_t));
>> -	parentbuf = (parent_t *)malloc(parentbuf_size);
>> -	if (!bstatbuf || !parentbuf) {
>> -		fprintf(stderr, _("unable to allocate buffers: %s\n"),
>> -			strerror(errno));
>> -		err_status = 1;
>> -		goto out;
>> -	}
>> +	int			ret;
>>   
>> -	if (do_bulkstat(parentbuf, &parentbuf_size, bstatbuf, fsfd, fshandlep) != 0)
>> -		err_status++;
>> -
>> -	if (err_status > 0)
>> -		fprintf(stderr, _("num errors: %d\n"), err_status);
>> +	if (handle)
>> +		ret = handle_walk_pptrs(handle, sizeof(*handle), pptr_print,
>> +				NULL);
>>   	else
>> -		printf(_("succeeded checking %llu inodes\n"),
>> -			(unsigned long long) inodes_checked);
>> -
>> -out:
>> -	free(bstatbuf);
>> -	free(parentbuf);
>> -	free(fshandlep);
>> -	return err_status;
>> -}
>> +		ret = fd_walk_pptrs(file->fd, pptr_print, NULL);
>> +	if (ret)
>> +		perror(file->name);
>>   
>> -static void
>> -print_parent_entry(parent_t *parent, int fullpath)
>> -{
>> -       printf(_("p_ino    = %llu\n"),  (unsigned long long) parent->p_ino);
>> -	printf(_("p_gen    = %u\n"),	parent->p_gen);
>> -	printf(_("p_reclen = %u\n"),	parent->p_reclen);
>> -	if (fullpath)
>> -		printf(_("p_name   = \"%s%s\"\n"), mntpt,
>> -					((char*)parent)+sizeof(struct parent));
>> -	else
>> -		printf(_("p_name   = \"%s\"\n"),
>> -					((char*)parent)+sizeof(struct parent));
>> +	return 0;
>>   }
>>   
>>   static int
>> -parent_list(int fullpath)
>> -{
>> -	void *handlep = NULL;
>> -	size_t handlen;
>> -	int error, i;
>> -	int retval = 1;
>> -	__u32 count;
>> -	parent_t *entryp;
>> -	parent_t *parentbuf = NULL;
>> -	char *path = file->name;
>> -	int pb_size = PARENTBUF_SZ;
>> -
>> -	/* XXXX for linux libhandle version - to set libhandle fsfd cache */
>> -	{
>> -		void *fshandle;
>> -		size_t fshlen;
>> -
>> -		if (path_to_fshandle(mntpt, &fshandle, &fshlen) != 0) {
>> -			fprintf(stderr, _("%s: failed path_to_fshandle \"%s\": %s\n"),
>> -				progname, path, strerror(errno));
>> -			goto error;
>> -		}
>> -		free_handle(fshandle, fshlen);
>> -	}
>> -
>> -	if (path_to_handle(path, &handlep, &handlen) != 0) {
>> -		fprintf(stderr, _("%s: path_to_handle failed for \"%s\"\n"), progname, path);
>> -		goto error;
>> -	}
>> -
>> -	do {
>> -		parentbuf = (parent_t *)realloc(parentbuf, pb_size);
>> -		if (!parentbuf) {
>> -			fprintf(stderr, _("%s: unable to allocate parent buffer: %s\n"),
>> -				progname, strerror(errno));
>> -			goto error;
>> -		}
>> +path_print(
>> +	const char		*mntpt,
>> +	struct path_list	*path,
>> +	void			*arg) {
>>   
>> -		if (fullpath) {
>> -			error = parentpaths_by_handle(handlep,
>> -						       handlen,
>> -						       parentbuf,
>> -						       pb_size,
>> -						       &count);
>> -		} else {
>> -			error = parents_by_handle(handlep,
>> -						   handlen,
>> -						   parentbuf,
>> -						   pb_size,
>> -						   &count);
>> -		}
>> -		if (error == ERANGE) {
>> -			pb_size *= 2;
>> -		} else if (error) {
>> -			fprintf(stderr, _("%s: %s call failed for \"%s\": %s\n"),
>> -				progname, fullpath ? "parentpaths" : "parents",
>> -				path, strerror(errno));
>> -			goto error;
>> -		}
>> -	} while (error == ERANGE);
>> +	char			buf[PATH_MAX];
>> +	size_t			len = PATH_MAX;
>> +	int			ret;
>>   
>> -	if (count == 0) {
>> -		/* no links for inode - something wrong here */
>> -		fprintf(stderr, _("%s: inode-path is missing\n"), progname);
>> -		goto error;
>> +	ret = snprintf(buf, len, "%s", mntpt);
>> +	if (ret != strlen(mntpt)) {
>> +		errno = ENOMEM;
>> +		return -1;
>>   	}
>>   
>> -	entryp = parentbuf;
>> -	for (i = 0; i < count; i++) {
>> -		print_parent_entry(entryp, fullpath);
>> -		entryp = (parent_t*) (((char*)entryp) + entryp->p_reclen);
>> -	}
>> +	ret = path_list_to_string(path, buf + ret, len - ret);
>> +	if (ret < 0)
>> +		return ret;
>> +	return 0;
>> +}
>>   
>> -	retval = 0;
>> -error:
>> -	free(handlep);
>> -	free(parentbuf);
>> -	return retval;
>> +int
>> +print_paths(
>> +	struct xfs_handle	*handle)
>> +{
>> +	int			ret;
>> +
>> +	if (handle)
>> +		ret = handle_walk_ppaths(handle, sizeof(*handle), path_print,
>> +				NULL);
>> + 	else
>> +		ret = fd_walk_ppaths(file->fd, path_print, NULL);
>> +	if (ret)
>> +		perror(file->name);
>> +	return 0;
>>   }
>>   
>>   int
>> -parent_f(int argc, char **argv)
>> +parent_f(
>> +	int			argc,
>> +	char			**argv)
>>   {
>> -	int c;
>> -	int listpath_flag = 0;
>> -	int check_flag = 0;
>> -	fs_path_t *fs;
>> -	static int tab_init;
>> +	struct xfs_handle	handle;
>> +	void			*hanp = NULL;
>> +	size_t			hlen;
>> +	struct fs_path		*fs;
>> +	char			*p;
>> +	uint64_t		ino = 0;
>> +	uint32_t		gen = 0;
>> +	int			c;
>> +	int			listpath_flag = 0;
>> +	int			ret;
>> +	static int		tab_init;
>>   
>>   	if (!tab_init) {
>>   		tab_init = 1;
>> @@ -394,46 +133,72 @@ parent_f(int argc, char **argv)
>>   	}
>>   	mntpt = fs->fs_dir;
>>   
>> -	verbose_flag = 0;
>> -
>> -	while ((c = getopt(argc, argv, "cpv")) != EOF) {
>> +	while ((c = getopt(argc, argv, "p")) != EOF) {
>>   		switch (c) {
>> -		case 'c':
>> -			check_flag = 1;
>> -			break;
>>   		case 'p':
>>   			listpath_flag = 1;
>>   			break;
>> -		case 'v':
>> -			verbose_flag++;
>> -			break;
>>   		default:
>>   			return command_usage(&parent_cmd);
>>   		}
>>   	}
>>   
>> -	if (!check_flag && !listpath_flag) /* default case */
>> -		exitcode = parent_list(listpath_flag);
>> -	else {
>> -		if (listpath_flag)
>> -			exitcode = parent_list(listpath_flag);
>> -		if (check_flag)
>> -			exitcode = parent_check();
>> +	/*
>> +	 * Always initialize the fshandle table because we need it for
>> +	 * the ppaths functions to work.
>> +	 */
>> +	ret = path_to_fshandle((char *)mntpt, &hanp, &hlen);
>> +	if (ret) {
>> +		perror(mntpt);
>> +		return 0;
>> + 	}
>> +
>> +	if (optind + 2 == argc) {
>> +		ino = strtoull(argv[optind], &p, 0);
>> +		if (*p != '\0' || ino == 0) {
>> +			fprintf(stderr,
>> +				_("Bad inode number '%s'.\n"),
>> +				argv[optind]);
>> +			return 0;
>> +		}
>> +		gen = strtoul(argv[optind + 1], &p, 0);
>> +		if (*p != '\0') {
>> +			fprintf(stderr,
>> +				_("Bad generation number '%s'.\n"),
>> +				argv[optind + 1]);
>> +			return 0;
>> +		}
>> +
>> +		memcpy(&handle, hanp, sizeof(handle));
>> +		handle.ha_fid.fid_len = sizeof(xfs_fid_t) -
>> +				sizeof(handle.ha_fid.fid_len);
>> +		handle.ha_fid.fid_pad = 0;
>> +		handle.ha_fid.fid_ino = ino;
>> +		handle.ha_fid.fid_gen = gen;
>> +
>>   	}
>>   
>> +	if (listpath_flag)
>> +		exitcode = print_paths(ino ? &handle : NULL);
>> +	else
>> +		exitcode = print_parents(ino ? &handle : NULL);
>> +
>> +	if (hanp)
>> +		free_handle(hanp, hlen);
>> +
>>   	return 0;
>>   }
>>   
>>   static void
>>   parent_help(void)
>>   {
>> -	printf(_(
>> +printf(_(
>>   "\n"
>>   " list the current file's parents and their filenames\n"
>>   "\n"
>> -" -c -- check the current file's file system for parent consistency\n"
>> -" -p -- list the current file's parents and their full paths\n"
>> -" -v -- verbose mode\n"
>> +" -p -- list the current file's paths up to the root\n"
>> +"\n"
>> +"If ino and gen are supplied, use them instead.\n"
>>   "\n"));
>>   }
>>   
>> @@ -444,9 +209,9 @@ parent_init(void)
>>   	parent_cmd.cfunc = parent_f;
>>   	parent_cmd.argmin = 0;
>>   	parent_cmd.argmax = -1;
>> -	parent_cmd.args = _("[-cpv]");
>> +	parent_cmd.args = _("[-p] [ino gen]");
>>   	parent_cmd.flags = CMD_NOMAP_OK;
>> -	parent_cmd.oneline = _("print or check parent inodes");
>> +	parent_cmd.oneline = _("print parent inodes");
>>   	parent_cmd.help = parent_help;
>>   
>>   	if (expert)
>> diff --git a/libfrog/paths.c b/libfrog/paths.c
>> index c7895e9..9fb0140 100644
>> --- a/libfrog/paths.c
>> +++ b/libfrog/paths.c
>> @@ -27,6 +27,7 @@
>>   #include "path.h"
>>   #include "input.h"
>>   #include "project.h"
>> +#include "list.h"
>>   #include <limits.h>
>>   
>>   extern char *progname;
>> @@ -632,3 +633,138 @@ fs_table_insert_project_path(
>>   		exit(1);
>>   	}
>>   }
>> +
>> +
>> +/* Structured path components. */
>> +
>> +struct path_list {
>> +	struct list_head	p_head;
>> +};
>> +
>> +struct path_component {
>> +	struct list_head	pc_list;
>> +	char			*pc_fname;
>> +};
>> +
>> +/* Initialize a path component with a given name. */
>> +struct path_component *
>> +path_component_init(
>> +	const char		*name)
>> +{
>> +	struct path_component	*pc;
>> +
>> +	pc = malloc(sizeof(struct path_component));
>> +	if (!pc)
>> +		return NULL;
>> +	INIT_LIST_HEAD(&pc->pc_list);
>> +	pc->pc_fname = strdup(name);
>> +	if (!pc->pc_fname) {
>> +		free(pc);
>> +		return NULL;
>> +	}
>> +	return pc;
>> +}
>> +
>> +/* Free a path component. */
>> +void
>> +path_component_free(
>> +	struct path_component	*pc)
>> +{
>> +	free(pc->pc_fname);
>> +	free(pc);
>> +}
>> +
>> +/* Change a path component's filename. */
>> +int
>> +path_component_change(
>> +	struct path_component	*pc,
>> +	void			*name,
>> +	size_t			namelen)
>> +{
>> +	void			*p;
>> +
>> +	p = realloc(pc->pc_fname, namelen + 1);
>> +	if (!p)
>> +		return -1;
>> +	pc->pc_fname = p;
>> +	memcpy(pc->pc_fname, name, namelen);
>> +	pc->pc_fname[namelen] = 0;
>> +	return 0;
>> +}
>> +
>> +/* Initialize a pathname. */
>> +struct path_list *
>> +path_list_init(void)
>> +{
>> +	struct path_list	*path;
>> +
>> +	path = malloc(sizeof(struct path_list));
>> +	if (!path)
>> +		return NULL;
>> +	INIT_LIST_HEAD(&path->p_head);
>> +	return path;
>> +}
>> +
>> +/* Empty out a pathname. */
>> +void
>> +path_list_free(
>> +	struct path_list	*path)
>> +{
>> +	struct path_component	*pos;
>> +	struct path_component	*n;
>> +
>> +	list_for_each_entry_safe(pos, n, &path->p_head, pc_list) {
>> +		path_list_del_component(path, pos);
>> +		path_component_free(pos);
>> +	}
>> +	free(path);
>> +}
>> +
>> +/* Add a parent component to a pathname. */
>> +void
>> +path_list_add_parent_component(
>> +	struct path_list	*path,
>> +	struct path_component	*pc)
>> +{
>> +	list_add(&pc->pc_list, &path->p_head);
>> +}
>> +
>> +/* Add a component to a pathname. */
>> +void
>> +path_list_add_component(
>> +	struct path_list	*path,
>> +	struct path_component	*pc)
>> +{
>> +	list_add_tail(&pc->pc_list, &path->p_head);
>> +}
>> +
>> +/* Remove a component from a pathname. */
>> +void
>> +path_list_del_component(
>> +	struct path_list	*path,
>> +	struct path_component	*pc)
>> +{
>> +	list_del_init(&pc->pc_list);
>> +}
>> +
>> +/* Convert a pathname into a string. */
>> +ssize_t
>> +path_list_to_string(
>> +	struct path_list	*path,
>> +	char			*buf,
>> +	size_t			buflen)
>> +{
>> +	struct path_component	*pos;
>> +	ssize_t			bytes = 0;
>> +	int			ret;
>> +
>> +	list_for_each_entry(pos, &path->p_head, pc_list) {
>> +		ret = snprintf(buf, buflen, "/%s", pos->pc_fname);
>> +		if (ret != 1 + strlen(pos->pc_fname))
>> +			return -1;
>> +		bytes += ret;
>> +		buf += ret;
>> +		buflen -= ret;
>> +	}
>> +	return bytes;
>> +}
>> diff --git a/libhandle/Makefile b/libhandle/Makefile
>> index fe1a2af..d3cea41 100644
>> --- a/libhandle/Makefile
>> +++ b/libhandle/Makefile
>> @@ -16,7 +16,7 @@ else
>>   LTLDFLAGS += -Wl,--version-script,libhandle.sym
>>   endif
>>   
>> -CFILES = handle.c jdm.c
>> +CFILES = handle.c jdm.c parent.c
>>   LSRCFILES = libhandle.sym
>>   
>>   default: ltdepend $(LTLIBRARY)
>> diff --git a/libhandle/handle.c b/libhandle/handle.c
>> index 878d14d..a70fa32 100644
>> --- a/libhandle/handle.c
>> +++ b/libhandle/handle.c
>> @@ -41,7 +41,6 @@ typedef union {
>>   } comarg_t;
>>   
>>   static int obj_to_handle(char *, int, unsigned int, comarg_t, void**, size_t*);
>> -static int handle_to_fsfd(void *, char **);
>>   static char *path_to_fspath(char *path);
>>   
>>   
>> @@ -214,8 +213,10 @@ handle_to_fshandle(
>>   	return 0;
>>   }
>>   
>> -static int
>> -handle_to_fsfd(void *hanp, char **path)
>> +int
>> +handle_to_fsfd(
>> +	void		*hanp,
>> +	char		**path)
>>   {
>>   	struct fdhash	*fdhp;
>>   
>> diff --git a/libhandle/parent.c b/libhandle/parent.c
>> new file mode 100644
>> index 0000000..f6be3bd
>> --- /dev/null
>> +++ b/libhandle/parent.c
>> @@ -0,0 +1,325 @@
>> +/*
>> + * Copyright (C) 2017 Oracle.  All Rights Reserved.
>> + *
>> + * Author: Darrick J. Wong <darrick.wong@oracle.com>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * as published by the Free Software Foundation; either version 2
>> + * of the License, or (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it would be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program; if not, write the Free Software Foundation,
>> + * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
>> + */
>> +#include "platform_defs.h"
>> +#include "xfs.h"
>> +#include "xfs_arch.h"
>> +#include "list.h"
>> +#include "path.h"
>> +#include "handle.h"
>> +#include "parent.h"
>> +
>> +/* Allocate a buffer large enough for some parent pointer records. */
>> +static inline struct xfs_pptr_info *
>> +xfs_pptr_alloc(
>> +      size_t                  nr_ptrs)
>> +{
>> +      struct xfs_pptr_info    *pi;
>> +
>> +      pi = malloc(XFS_PPTR_INFO_SIZEOF(nr_ptrs));
>> +      if (!pi)
>> +              return NULL;
>> +      memset(pi, 0, sizeof(struct xfs_pptr_info));
>> +      pi->pi_ptrs_size = nr_ptrs;
>> +      return pi;
>> +}
>> +
>> +/* Walk all parents of the given file handle. */
>> +static int
>> +handle_walk_parents(
>> +	int			fd,
>> +	struct xfs_handle	*handle,
>> +	walk_pptr_fn		fn,
>> +	void			*arg)
>> +{
>> +	struct xfs_pptr_info	*pi;
>> +	struct xfs_parent_ptr	*p;
>> +	unsigned int		i;
>> +	ssize_t			ret = -1;
>> +
>> +	pi = xfs_pptr_alloc(4);
>> +	if (!pi)
>> +		return -1;
>> +
>> +	if (handle) {
>> +		memcpy(&pi->pi_handle, handle, sizeof(struct xfs_handle));
>> +		pi->pi_flags = XFS_PPTR_IFLAG_HANDLE;
>> +	}
>> +
>> +	ret = ioctl(fd, XFS_IOC_GETPPOINTER, pi);
>> +	while (!ret) {
>> +		if (pi->pi_flags & XFS_PPTR_OFLAG_ROOT) {
>> +			ret = fn(pi, NULL, arg);
>> +			break;
>> +		}
>> +		if (pi->pi_ptrs_used == 0)
>> +			break;
>> +		for (i = 0; i < pi->pi_ptrs_used; i++) {
>> +			p = XFS_PPINFO_TO_PP(pi, i);
>> +			ret = fn(pi, p, arg);
>> +			if (ret)
>> +				goto out_pi;
>> +		}
>> +		ret = ioctl(fd, XFS_IOC_GETPPOINTER, pi);
>> +	}
>> +
>> +out_pi:
>> +	free(pi);
>> +	return ret;
>> +}
>> +
>> +/* Walk all parent pointers of this handle. */
>> +int
>> +handle_walk_pptrs(
>> +	void			*hanp,
>> +	size_t			hlen,
>> +	walk_pptr_fn		fn,
>> +	void			*arg)
>> +{
>> +	char			*mntpt;
>> +	int			fd;
>> +
>> +	if (hlen != sizeof(struct xfs_handle)) {
>> +		errno = EINVAL;
>> +		return -1;
>> +	}
>> +
>> +	fd = handle_to_fsfd(hanp, &mntpt);
>> +	if (fd < 0)
>> +		return -1;
>> +
>> +	return handle_walk_parents(fd, hanp, fn, arg);
>> +}
>> +
>> +/* Walk all parent pointers of this fd. */
>> +int
>> +fd_walk_pptrs(
>> +	int			fd,
>> +	walk_pptr_fn		fn,
>> +	void			*arg)
>> +{
>> +	return handle_walk_parents(fd, NULL, fn, arg);
>> +}
>> +
>> +struct walk_ppaths_info {
>> +	walk_ppath_fn			fn;
>> +	void				*arg;
>> +	char				*mntpt;
>> +	struct path_list		*path;
>> +	int				fd;
>> +};
>> +
>> +struct walk_ppath_level_info {
>> +	struct xfs_handle		newhandle;
>> +	struct path_component		*pc;
>> +	struct walk_ppaths_info		*wpi;
>> +};
>> +
>> +static int handle_walk_parent_paths(struct walk_ppaths_info *wpi,
>> +		struct xfs_handle *handle);
>> +
>> +static int
>> +handle_walk_parent_path_ptr(
>> +	struct xfs_pptr_info		*pi,
>> +	struct xfs_parent_ptr		*p,
>> +	void				*arg)
>> +{
>> +	struct walk_ppath_level_info	*wpli = arg;
>> +	struct walk_ppaths_info		*wpi = wpli->wpi;
>> +	unsigned int			i;
>> +	int				ret = 0;
>> +
>> +	if (pi->pi_flags & XFS_PPTR_OFLAG_ROOT)
>> +		return wpi->fn(wpi->mntpt, wpi->path, wpi->arg);
>> +
>> +	for (i = 0; i < pi->pi_ptrs_used; i++) {
>> +		p = XFS_PPINFO_TO_PP(pi, i);
>> +		ret = path_component_change(wpli->pc, p->xpp_name,
>> +				p->xpp_namelen);
>> +		if (ret)
>> +			break;
>> +		wpli->newhandle.ha_fid.fid_ino = p->xpp_ino;
>> +		wpli->newhandle.ha_fid.fid_gen = p->xpp_gen;
>> +		path_list_add_parent_component(wpi->path, wpli->pc);
>> +		ret = handle_walk_parent_paths(wpi, &wpli->newhandle);
>> +		path_list_del_component(wpi->path, wpli->pc);
>> +		if (ret)
>> +			break;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * Recursively walk all parents of the given file handle; if we hit the
>> + * fs root then we call the associated function with the constructed path.
>> + */
>> +static int
>> +handle_walk_parent_paths(
>> +	struct walk_ppaths_info		*wpi,
>> +	struct xfs_handle		*handle)
>> +{
>> +	struct walk_ppath_level_info	*wpli;
>> +	int				ret;
>> +
>> +	wpli = malloc(sizeof(struct walk_ppath_level_info));
>> +	if (!wpli)
>> +		return -1;
>> +	wpli->pc = path_component_init("");
>> +	if (!wpli->pc) {
>> +		free(wpli);
>> +		return -1;
>> +	}
>> +	wpli->wpi = wpi;
>> +	memcpy(&wpli->newhandle, handle, sizeof(struct xfs_handle));
>> +
>> +	ret = handle_walk_parents(wpi->fd, handle, handle_walk_parent_path_ptr,
>> +			wpli);
>> +
>> +	path_component_free(wpli->pc);
>> +	free(wpli);
>> +	return ret;
>> +}
>> +
>> +/*
>> + * Call the given function on all known paths from the vfs root to the inode
>> + * described in the handle.
>> + */
>> +int
>> +handle_walk_ppaths(
>> +	void			*hanp,
>> +	size_t			hlen,
>> +	walk_ppath_fn		fn,
>> +	void			*arg)
>> +{
>> +	struct walk_ppaths_info	wpi;
>> +	ssize_t			ret;
>> +
>> +	if (hlen != sizeof(struct xfs_handle)) {
>> +		errno = EINVAL;
>> +		return -1;
>> +	}
>> +
>> +	wpi.fd = handle_to_fsfd(hanp, &wpi.mntpt);
>> +	if (wpi.fd < 0)
>> +		return -1;
>> +	wpi.path = path_list_init();
>> +	if (!wpi.path)
>> +		return -1;
>> +	wpi.fn = fn;
>> +	wpi.arg = arg;
>> +
>> +	ret = handle_walk_parent_paths(&wpi, hanp);
>> +	path_list_free(wpi.path);
>> +
>> +	return ret;
>> +}
>> +
>> +/*
>> + * Call the given function on all known paths from the vfs root to the inode
>> + * referred to by the file description.
>> + */
>> +int
>> +fd_walk_ppaths(
>> +	int			fd,
>> +	walk_ppath_fn		fn,
>> +	void			*arg)
>> +{
>> +	struct walk_ppaths_info	wpi;
>> +	void			*hanp;
>> +	size_t			hlen;
>> +	int			fsfd;
>> +	int			ret;
>> +
>> +	ret = fd_to_handle(fd, &hanp, &hlen);
>> +	if (ret)
>> +		return ret;
>> +
>> +	fsfd = handle_to_fsfd(hanp, &wpi.mntpt);
>> +	if (fsfd < 0)
>> +		return -1;
>> +	wpi.fd = fd;
>> +	wpi.path = path_list_init();
>> +	if (!wpi.path)
>> +		return -1;
>> +	wpi.fn = fn;
>> +	wpi.arg = arg;
>> +
>> +	ret = handle_walk_parent_paths(&wpi, hanp);
>> +	path_list_free(wpi.path);
>> +
>> +	return ret;
>> +}
>> +
>> +struct path_walk_info {
>> +	char			*buf;
>> +	size_t			len;
>> +};
>> +
>> +/* Helper that stringifies the first full path that we find. */
>> +static int
>> +handle_to_path_walk(
>> +	const char		*mntpt,
>> +	struct path_list	*path,
>> +	void			*arg)
>> +{
>> +	struct path_walk_info	*pwi = arg;
>> +	int			ret;
>> +
>> +	ret = snprintf(pwi->buf, pwi->len, "%s", mntpt);
>> +	if (ret != strlen(mntpt)) {
>> +		errno = ENOMEM;
>> +		return -1;
>> +	}
>> +
>> +	ret = path_list_to_string(path, pwi->buf + ret, pwi->len - ret);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	return WALK_PPATHS_ABORT;
>> +}
>> +
>> +/* Return any eligible path to this file handle. */
>> +int
>> +handle_to_path(
>> +	void			*hanp,
>> +	size_t			hlen,
>> +	char			*path,
>> +	size_t			pathlen)
>> +{
>> +	struct path_walk_info	pwi;
>> +
>> +	pwi.buf = path;
>> +	pwi.len = pathlen;
>> +	return handle_walk_ppaths(hanp, hlen, handle_to_path_walk, &pwi);
>> +}
>> +
>> +/* Return any eligible path to this file description. */
>> +int
>> +fd_to_path(
>> +	int			fd,
>> +	char			*path,
>> +	size_t			pathlen)
>> +{
>> +	struct path_walk_info	pwi;
>> +
>> +	pwi.buf = path;
>> +	pwi.len = pathlen;
>> +	return fd_walk_ppaths(fd, handle_to_path_walk, &pwi);
>> +}
>> diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h
>> index e3ce233..aa613f9 100644
>> --- a/libxfs/xfs_fs.h
>> +++ b/libxfs/xfs_fs.h
>> @@ -610,6 +610,14 @@ struct xfs_pptr_info {
>>   #define XFS_PPINFO_TO_PP(info, idx)    \
>>   	(&(((struct xfs_parent_ptr *)((char *)(info) + sizeof(*(info))))[(idx)]))
>>   
>> +#define XFS_PPTR_ALL_IFLAGS    (XFS_PPTR_IFLAG_HANDLE)
>> +
>> +/* partial results only */
>> +#define XFS_PPTR_OFLAG_PARTIAL (1U << 0)
>> +
>> +/* target was the root directory */
>> +#define XFS_PPTR_OFLAG_ROOT    (1U << 1)
> 
> Uhoh, I forgot about this chunk, which should be in the kernel patches
> somewhere I guess...
> 
> --D
> 

Do we want to keep these?  Should I add behavior of these in the kernel 
side set?

Allison

>> +
>>   /*
>>    * ioctl limits
>>    */
>> diff --git a/scrub/inodes.c b/scrub/inodes.c
>> index ccfb9e0..3fbcd1a 100644
>> --- a/scrub/inodes.c
>> +++ b/scrub/inodes.c
>> @@ -31,6 +31,7 @@
>>   #include "xfs_scrub.h"
>>   #include "common.h"
>>   #include "inodes.h"
>> +#include "parent.h"
>>   
>>   /*
>>    * Iterate a range of inodes.
>> @@ -293,3 +294,28 @@ xfs_open_handle(
>>   	return open_by_fshandle(handle, sizeof(*handle),
>>   			O_RDONLY | O_NOATIME | O_NOFOLLOW | O_NOCTTY);
>>   }
>> +
>> +/* Construct a description for an inode. */
>> +void
>> +xfs_scrub_ino_descr(
>> +	struct scrub_ctx	*ctx,
>> +	struct xfs_handle	*handle,
>> +	char			*buf,
>> +	size_t			buflen)
>> +{
>> +	uint64_t		ino;
>> +	xfs_agnumber_t		agno;
>> +	xfs_agino_t		agino;
>> +	int			ret;
>> +
>> +	ret = handle_to_path(handle, sizeof(struct xfs_handle), buf, buflen);
>> +	if (ret >= 0)
>> +		return;
>> +
>> +	ino = handle->ha_fid.fid_ino;
>> +	agno = ino / (1ULL << (ctx->inopblog + ctx->agblklog));
>> +	agino = ino % (1ULL << (ctx->inopblog + ctx->agblklog));
>> +	snprintf(buf, buflen, _("inode %"PRIu64" (%u/%u)"), ino, agno,
>> +			agino);
>> +}
>> +
>> diff --git a/scrub/inodes.h b/scrub/inodes.h
>> index 693cb05..e94de0a 100644
>> --- a/scrub/inodes.h
>> +++ b/scrub/inodes.h
>> @@ -28,5 +28,7 @@ bool xfs_scan_all_inodes(struct scrub_ctx *ctx, xfs_inode_iter_fn fn,
>>   		void *arg);
>>   
>>   int xfs_open_handle(struct xfs_handle *handle);
>> +void xfs_scrub_ino_descr(struct scrub_ctx *ctx, struct xfs_handle *handle,
>> +		char *buf, size_t buflen);
>>   
>>   #endif /* XFS_SCRUB_INODES_H_ */
>> diff --git a/scrub/phase5.c b/scrub/phase5.c
>> index 01038f7..ecaaaaa 100644
>> --- a/scrub/phase5.c
>> +++ b/scrub/phase5.c
>> @@ -245,16 +245,11 @@ xfs_scrub_connections(
>>   	void			*arg)
>>   {
>>   	bool			*pmoveon = arg;
>> -	char			descr[DESCR_BUFSZ];
>> +	char			descr[PATH_MAX];
>>   	bool			moveon = true;
>> -	xfs_agnumber_t		agno;
>> -	xfs_agino_t		agino;
>>   	int			fd = -1;
>>   
>> -	agno = bstat->bs_ino / (1ULL << (ctx->inopblog + ctx->agblklog));
>> -	agino = bstat->bs_ino % (1ULL << (ctx->inopblog + ctx->agblklog));
>> -	snprintf(descr, DESCR_BUFSZ, _("inode %"PRIu64" (%u/%u)"),
>> -			(uint64_t)bstat->bs_ino, agno, agino);
>> +	xfs_scrub_ino_descr(ctx, handle, descr, PATH_MAX);
>>   	background_sleep();
>>   
>>   	/* Warn about naming problems in xattrs. */
>> -- 
>> 2.7.4
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html